Cerebrospinal lactate dehydrogenase and serum procalcitonin in the diagnosis of meningitis

Abstract

Background Meningitis is inflammation of the membranes that cover the brain, spinal cord, and the intervening cerebrospinal fluid..Aim The aim of this paper was to assess the diagnostic role of cerebrospinal lactate dehydrogenase (LDH) and serum procalcitonin (PCT) in meningitis and to differentiate septic from aseptic meningitis.Patients and methods The cases were divided into septic meningitis (group I), aseptic meningitis (group II), and meningism (group III) and 100 control cases of complaints other than central nervous system (CNS) infection. All patients were evaluated by full clinical examination, laboratory investigation (complete blood count, erythrocyte sedimentation rate, C-reactive protein, and random blood sugar, liver and renal function tests, and blood culture), lumbar puncture for cerebrospinal fluid examination, cerebrospinal LDH by spectrophotometer, serum PCT in selected patients, computed tomography, and MRI in complicated cases.Results Cerebrospinal LDH 100% of 139 cases in septic meningitis and 98% of 104 cases in aseptic meningitis were elevated above normal range. All cases of meningism show normal range. Furthermore, serum PCT testing was positive in all patients with septic meningitis, while serum PCT testing is positive in 35 (34%) patients with aseptic meningitis and negative in 69 (66%) patients and serum PCT-Q testing was negative in all patients with meningism. Controls were assessed for normal serum PCT level.Conclusion Cerebrospinal LDH can be used only as a preliminary screening test, whereas PCT-Q was a good diagnostic marker for distinguishing septic from aseptic meningitis.